Eric Houbron

Hydraulic retention time impact of treated recirculated leachate on the hydrolytic kinetic rate of coffee pulp in an acidogenic reactor.

This study attempted to investigate the impact of HRT of treated leachate recirculation on hydrolysis solubilization rate of coffee pulp in an acidogenic reactor. Coffee pulp presents more than 70% of organic matter and around of 30% of lignin and cellulose. Five lab scale reactors of 20 litres were used. Each reactor was fed with 5 kg of fresh coffee pulp and anaerobic sludge was used as inoculate. HRT of 0.5, 1, 3 and 10 days were applied. Each experiment shows that Total, Soluble and VFA COD appear rapidly in the removed leachate. HRT have a great impact on hydrolytic rate with an optimal value of 32,000 mg x L(-1) x d(-1).Low HRT increases hydrolysis rate and in consequence reduces duration of the hydrolytic phase. Also composition and concentration of VFA are influenced by HRT. Low ones favour acetic acid production and high ones permit the production of butyric. Low HRT generates leachate more easily fermentable. Efficiency of solubilization and acidification are independent of the HRT and present average values of 78% and 65% respectively. By batch feeding solid and continuous recirculation of treated leachate, HRT and SRT could be dissociated, where solid had a very high retention without problems of load, mixing and inhibition, and liquid could be recirculated with a very high rate. Under these low HRT condition, the first reactor of a two stage anaerobic system could reduces the hydrolysis duration of organic solid waste like coffee pulp and generate an optimal leachate for the methanization process.

Prevention of the development of polluting characteristics in cooking water residue from nixtamalisation of corn by removing solid lime particles

1 Colegio de Postgraduados – Campus C ordoba, Programa de Innovaci on Agroalimentaria Sustentable, Km. 348 Carr. Fed. C ordobaVeracruz, Amatl an de los Reyes, Veracruz, C.P. 94946, Mexico 2 School of Nutrition and Food Sciences, Agricultural Center, Louisiana State University, Baton Rouge, LA 70803-4200, USA 3 Centro de Investigaci on y de Estudios Avanzados del I.P.N, Unidad Quer etaro, Libramiento Norponiente No. 2000, Fracc. Real de Juriquilla, Quer etaro, Qro, C.P. 76230, Mexico 4 Facultad de Ciencias Biol ogicas y Agropecuarias, Universidad Veracruzana, Regi on Orizaba-C ordoba, Camino Pe~ nuela-Amatl an s/n, Municipio de Amatl an de los Reyes, Veracruz, C.P. 94945, Mexico 5 Facultad de Ciencias Qu ımicas, Laboratorio de Gesti on y Control Ambiental, Universidad Veracruzana, Orizaba, Ver, 94340, Mexico

TRATAMIENTO DE VINAZAS EN UN REACTOR DE LECHO FLUIDIZADO INVERSO ANAEROBIO

En la produccion de etanol se generan vinazas, efluentes con pH acido y elevada demanda quimica de oxigeno (DQO). Los sistemas de tratamiento anaerobio con biopelicula son una tecnologia consolidada para tratamiento de efluentes industriales. El reactor de lecho fluidizado inverso anaerobio (LFI), empleado en el tratamiento de efluentes de alta carga, utiliza un soporte que proporciona una gran superficie y un bajo requerimiento de energia para la fluidizacion del lecho. Este trabajo evalua el desempeno de un LFI, empleando Extendospher ® como soporte y tratando efluentes de la produccion de etanol. El reactor arranco por lotes, posteriormente opero en con - tinuo a diferentes cargas organicas volumetricas: 0.5, 1.0, 3.3, 6.8 y 10.4 gDQO/L d. Ademas, se evaluaron diferentes tiempos de residencia hidraulica (TRH): 10, 5 y 1 d ias . El sistema alcanzo las siguientes eficiencias promedio de remocion de DQO: 81 % para la operacion en lotes, y 58, 67, 59 y 50 % con cargas de 0.5, 1.0, 3.3, 6.8 gDQO/L d respectivamente. Para la carga de 10.4 gDQO/L d, la eficiencia promedio de remocion de DQO fue 38 %, en esta condicion el reactor presento inestabilidad y disminucion del rendimiento de metano. La generacion de metano inicio hasta los 110 dias de operacion del reactor a una carga de 1.0 gDQO/L d. El sistema alcanzo un rendimiento de metano desde 0.15 hasta 0.34 LCH 4 /gDQO removida . El reactor ope - rando a una carga constante de 6.4 gDQO/L d, y TRH de 1 dia, alcanzo una eficiencia promedio de remocion de DQO de 52 %

Methane yield and microscopic observation as monitoring biofilm behaviour parameters, during start up phase of anaerobic inverse fluidized bed reactor

Anaerobic biofilm behavior on polyethylene and Extendosphere™ supports was evaluated during start-up of an inverse fluidized bed reactor using methane yield and microscopic observation as parameter monitoring techniques. Two anaerobic inverse fluidized bed reactors were used, one filled with triturated polyethylene as solid carrier material (diameter = 380 μm, density = 926 kg/m 3 ) and the other with Extendosphere™ (diameter = 147 μm, density = 700 kg/m 3 ). Each support material was used at up to 25% of its working volume (polyethylene = 1.2 l, Extendosphere™ = 1.9 l). Both reactors were started up in sequencing batch mode, applying organic loading rates of 0.5 to 14 g COD/l.d. Both supports exhibited rapid biofilm growth during start-up. Maximum surface colonization was 46% with the polyethylene and 100% with Extendosphere™. Both supports had a methane yield of 0.298 l CH 4 /g COD at 10 and 14 g COD/l.d, respectively. Digital microscopic observation results coincided with methane yield results, confirming each to be viable for parameter monitoring of biofilm growth. Data generated by these two techniques is different and complementary, and in conjunction they constitute a highly effective monitoring method of biofilm growth. Key words: Anaerobic digestion, biofilm, inverse fluidized bed reactor, methane yield.